1. Field of the Invention
The present invention relates to gas-liquid contacting, and, more especially, to the physical and/or chemical spray scrubbing of a gas stream in a cocurrent gas-liquid phase contactor therefor.
2. Description of the Prior Art
It is ofttimes required and/or necessary to purify or otherwise treat effluent gas streams, especially if same are destined for venting into the atmosphere. Such purification/treatment is typically deemed the "sanitation" thereof, and usually is carried out in any one of a great number of known gas-liquid phase contactors, the operation of each of which must be strictly optimized in order to effect true or acceptable purification of such gas streams.
And optimization may be attempted via any one or more of several different routes, for example:
(a) the velocity of the inlet gas stream may be reduced and strong atomization may be effected at a high rate of flow and under great pressure. This is conveniently accomplished in absorption columns; compare, e.g., those described in U.S. Pat. No. 2,409,088 and in Chapter 20 of Perry's Chemical Engineering Handbook; PA1 (b) or the velocity of the inlet gas stream may be increased, and lesser atomization may be effected, resulting in enhanced phase contacting, such as is attained in devices of venturi type, one of which is described, for example, in Belgian Pat. No. 498,107. See also the contacting apparatus disclosed in U.S. Pat. No. 3,733,789.
In each of the aforementioned alternatives, the area of actual contacting of the respective phases, or "contact surface", must be increased in order to enhance efficiency, i.e., the transfer of heat and/or mass transfer must be improved.
And to increase the contact surfaces necessarily requires the expenditure or utilization of extra energy: either on the liquid side via strong atomization, which is effected in a tower; or on the gas side via atomization in a venturi, wherein a significant loss in pressure has to be tolerated. The size of the blower, moreover, must then be increased as a function of the drop in pressure; furthermore, if the gas flow is large, blowers with larger dimensions are required, and still further, their design is complicated by the need to use special materials when treating corrosive gases, which mandates custom equipment.